I too have Schaefer blocks but the half moon that already has the springs.

You might check with the manufacrue of your mast. They may have a mast base with and organizer flange.

On my vessel I built a 316 SS hourseshoe that fits around the mast step and mounted the blocks on that . It had 14 winches when I made the purchase. Now it''s down to 6. Every line runs back to the cockpit now . Much better for singlehandling

Here are a couple links to pictures. Hope this helps in your search and/or ideas.